Background <p>Medication errors (MEs) remain a leading cause of preventable harm in healthcare systems worldwide, contributing to adverse drug events, morbidity, increased healthcare costs, prolonged hospitalization, and mortality. The paediatric population is particularly susceptible to MEs due to the need for individualized dosing based on weight and age, which introduces additional complexity for healthcare providers. Although considerable research has been conducted on this issue, existing studies have predominantly focused on secondary and tertiary healthcare institutions, where specialized personnel and resources are more readily available. In contrast, in certain settings, primary healthcare facilities are staffed by non-specialist healthcare professionals who face unique challenges in paediatric care due to limited training and insufficient clinical support. This disparity highlights a critical gap in the literature and underscores the urgent need for targeted interventions to improve medication safety in primary care settings.</p> Objective <p>The study was undertaken with the aim of determining the prevalence and types of medication errors committed by nurses among children under 5 years at three (3) primary healthcare facilities in the western region of Ghana.</p> Materials and methods <p>Six (6) months retrospective data was taken to assess the prevalence and types of medication errors. Data was gathered using a checklist from records of paediatric patients aged ≤ 5years who visited the three primary health care facilities from 1st July 2020–31st December 2020 and attended to by a nurse clinician. MEs were categorised into dosage error, frequency error, prescribing error and administration error. Based on the number of errors occurring per treatment, errors were classified as No error, one error and two or multiple errors. Data was analysed using Statistical Package for the Social Sciences (SPSS) version 23.</p> Results <p>Out of the 341 paediatric folders examined, the prevalence of MEs among children under 5years from the three primary health facilities was 59.3%. Dosage errors accounted for 47.3% of identified errors, followed by frequency errors (17.8%), prescribing errors of 14.8% and administering errors 6.1%.</p> Conclusion <p>The prevalence of medication errors among children under five years across the three primary health care facilities was significantly high (59.3%).</p>